Bass performance is important to an acoustic system. Most speakers employ a vented bass-reflect design to improve sound efficiency at low frequency. FIG. 1 schematically illustrates a cross-sectional view of a conventional vented bass-reflect speaker 100. The speaker 100 may include a speaker box 101, a speaker driver 103 disposed on a sidewall of the speaker box 101, and a bass tube (also called “bass port”) 105 disposed inside the speaker box 101. The bass tube 105 is open at both ends. Therefore, rear bass radiation may be reflected inside the speaker box 101 and educed through the bass tube 105, which may enhance the bass performance. However, the bass tube 105 may occupy some inner space of the speaker box 101, which reduces the acoustic volume and thus limits the bass reproduction range. Therefore, there is need for a speaker with improved acoustic performance.